Determination of bisphenol A in exposed bottled water samples to direct sun light using multi walled carbon nanotubes as solid phase extraction sorbent

Abstract

Polycarbonate plastics (PC) containing bisphenol A (BPA) are used for the production of bottles for storage drinking water. Trace amounts of BPA have been detected in ten different brands of bottled water samples from Khartoum supermarkets. Residues of BPA in bottled water were pre-concentrated using solid-phase extraction and determined by high performance liquid chromatography with fluorescence detector. Recently, multiwalled carbon nanotubes (MWCNTs) have great attention because of their application in many fields. MWCNTs were used as adsorptive material for solid phase extraction which it was packed in mini column prior to pre-concentration step. The results indicate that the mean concentration of BPA in ten bottled water brands was 4.28 ng/ml for those stored at room temperature (25°C) and 11.81 ng/ml for those exposed to direct sunlight (40°C). The concentration of BPA in bottled water exposed to direct sun light was significantly higher than those stored at room temperature. Recovery of BPA from water was 92.5%. Detection limit for BPA were 0.30 ng/ml. Good correlation coefficients (˃0.9996) were obtained. The method has been successfully applied for the determination of trace BPA in bottled water samples.